System and method to detection of particles in liquid or in air

ABSTRACT

A method and system for detecting foreign particles in a liquid, the method and system include transmitting transmitted pulses of radiation, by a transmitter, towards a liquid conduit that is filled with liquid; wherein the transmitted pulses comprises pulses that differ from each by being associated with absorbance frequencies of different foreign particles; receiving, by a receiver, received pulses that propagated through liquid as a result of the transmission of the multiple transmitted pulses; comparing between the transmitted pulses and the received pulses to provide a comparison result; and determining a liquid contamination based on the comparison result.

This patent application claims priority from Russian patent applicationserial number 046217 filing date 21 Jul. 2015, which is incorporatedherein in its entirety.

FIELD OF THE INVENTION

The invention refers to measuring equipment field. In particular newmethod and instrument design for water and air quality monitoring aresubject to consideration. Method and design of the instrument allowscommunicating air and watering pollution data to control center in fewseconds identifying contamination location.

BACKGROUND

Water clarity and turbidity depends on suspended mechanical impuritiescontent. The more admixtures in the water, the higher turbidity and lessclarity water features. Transparency is defined by path length of thebeam penetrating deep into the water and depends on beam wave length.Ultraviolet beams are easily passing through water and infraredones—poorly. Clearing index is used to assess water quality andimpurities content.

Due to human impact natural water is subject to contamination withvarious substances deteriorating its quality. Water quality isunderstood as an aggregate of physical, chemical, biological andbacteriological qualities. Pollutions to water medium vary thesequalities.

BRIEF DESCRIPTION OF THE DRAWINGS

The subject matter regarded as the invention is particularly pointed outand distinctly claimed in the concluding portion of the specification.The invention, however, both as to organization and method of operation,together with objects, features, and advantages thereof, may best beunderstood by reference to the following detailed description when readwith the accompanying drawings in which:

FIG. 1 illustrates a foreign particle detection system (system) and aliquid conduit according to an embodiment of the invention:

FIG. 2 illustrates a receiver and a transmitter and a fluid conduitaccording to an embodiment of the invention:

FIG. 3 illustrates a transmitter according to an embodiment of theinvention;

FIG. 4 illustrates a receiver according to an embodiment of theinvention;

FIG. 5 illustrates a system that includes a bubble flask according to anembodiment of the invention;

FIG. 6 illustrates a bubble flask according to an embodiment of theinvention;

FIG. 7 illustrates a bubble flask according to an embodiment of theinvention;

FIG. 8 illustrates a system according to an embodiment of the invention;

FIG. 9 illustrates a system and a monitored device according to anembodiment of the invention;

FIG. 10 illustrates two systems and a monitored device according to anembodiment of the invention;

FIG. 11 illustrates a system and a monitored device according to anembodiment of the invention;

FIG. 12 multiple sampling points and an irrigation system according toan embodiment of the invention;

FIG. 13 illustrates a system and a cleaning unit according to anembodiment of the invention;

FIG. 14 illustrates a switch according to an embodiment of theinvention;

FIG. 15 illustrates a system and multiple monitored device according toan embodiment of the invention;

FIG. 16 illustrates a system and a sampling unit according to anembodiment of the invention; and

FIG. 17 illustrates a method according to an embodiment of theinvention.

DETAILED DESCRIPTION OF THE DRAWINGS

In the following detailed description, numerous specific details are setforth in order to provide a thorough understanding of the invention.However, it will be understood by those skilled in the art that thepresent invention may be practiced without these specific details. Inother instances, well-known methods, procedures, and components have notbeen described in detail so as not to obscure the present invention.

The subject matter regarded as the invention is particularly pointed outand distinctly claimed in the concluding portion of the specification.The invention, however, both as to organization and method of operation,together with objects, features, and advantages thereof, may best beunderstood by reference to the following detailed description when readwith the accompanying drawings.

It will be appreciated that for simplicity and clarity of illustration,elements shown in the figures have not necessarily been drawn to scale.For example, the dimensions of some of the elements may be exaggeratedrelative to other elements for clarity. Further, where consideredappropriate, reference numerals may be repeated among the figures toindicate corresponding or analogous elements.

Because the illustrated embodiments of the present invention may for themost part, be implemented using electronic components and circuits knownto those skilled in the art, details will not be explained in anygreater extent than that considered necessary as illustrated above, forthe understanding and appreciation of the underlying concepts of thepresent invention and in order not to obfuscate or distract from theteachings of the present invention.

Any reference in the specification to a method should be applied mutatismutandis to a system capable of executing the method.

Any reference in the specification to a system should be applied mutatismutandis to a method that may be executed by the system.

Remote sensing methods shall solve contamination detection issue meaningcontamination fact finding. All remote sensing methods are based ondifference in electrical or optical properties of pure water and oil-cutwater. The following techniques can be referred to remote methods:photographic method; passive method based on direct and water surfacereflected diffuse solar radiation registration; method based onfluorescence spectra registration induced by impurities exposure topowerful UV radiation source; radiometric method and radio-reflectionmethod.

One more method is available based on direct and direct and watersurface reflected diffuse solar radiation recording by aircraftequipment set. Spectral radiometer or differential radiometer is used aslogging unit. When using the last one either difference in radiationintensity of two wave-length intervals or intensity difference of twoorthogonal constituent parts of reflected radiation is recorded. Maximumcontrast has been received in <0.4 and >0.6 μm. Its weakness is instrong dependence on meteorological conditions: impurities detection ispossible at totally overcast sky only (in the absence of direct solarradiation), along with dependence from sun altitude angle above horizon.

To assess treated water on-site and in flow-through mode, water qualitymonitoring devices using optical methods have gained widespread use,meaning based on water clarity principle. However “clarity” can giveonly generalized picture of process mode regularity or abnormality, butit does not allow quantifying impurities in the water. Besides that suchdevices are operable only limited time due to fast contamination ofglass surfaces, and quite often periodic cleaning of such surfaces isimpossible with analyzed water flowing through.

As a rule, contact type in-flow turbidity meters are optic turbiditymeters or haze meters [Andryeyev V. S., Popechitelev Ye. P. Laboratoryinstruments to explore liquid fluids.—L: Mashinostroyeniye.—1981.—pages99-101]. Their general lack is contamination of transmitter's andreceiver's transparent windows being in direct contact with controlledmedium causing very high inaccuracy of measurements, or eveninstrument's malfunction. There are a number of ways to minimize thisfactor for example glass heating, glass coating with water-proofingagents, mechanical collectors use, variable thickness working layermeasuring cells use, etc. (Belyakov V. L. Oil and water field treatmentautomation.—M.: Nedra—1988.—page 133). All of them are rathercomplicated and of low efficiency.

One of effective ways to eliminate windows contamination is to usefour-beam circuit providing for two transmitters and two photoelectricreceivers. The device operating as per such circuit (GB 2251682,G01N21/49, 21/59, published 15 Jul. 1992], contains measurement chamberwith controlled liquid, the walls of which have two transmitters and twophotoelectric receivers, where first photoelectric receiver's axisconsists with axis of the first transmitter being opposite to it and isperpendicular to the axis of second transmitter, and secondphotoelectric receiver's axis consists with axis of the secondtransmitter being opposite to it and is perpendicular to the axis of thefirst transmitter. Transmitters' and photoelectric receivers' outputsare connected to signal control and processing circuit. Alternativeactivation of transmitters allows to get two signals from eachphotoelectric receiver, one of which corresponds to direct attenuatedradiation (turbidimetry), and the second one—scattered radiation(nephelometry). Four signals received shall be put into special mathexpression calculation of which allows getting final result free fromclarity instability of each window. However under severe contaminationsespecially in the presence of sticky phase such device becomes unfit forservice.

Various non-contacting haze-meters are available with air gap betweenoptical components and liquid medium. They are normally based on designproviding free surface of permanently flowing constant level liquid overwhich transmitting source is installed. Photoelectric receiver isinstalled either over same surface of liquid or perpendicular tooutflowing jet. Normally output signal of photoelectric receiver isproportional to suspended solids concentration.

For example WTM500 turbidity meter of Sigrist Photometer AG(Switzerland) make [Rogner A. Turbidity Measurement in drinking waterapplications—new requirements and approaches//InternationalEnvironmental Technology.—Vol. 8, 6.—1998.—Pp. 9-10] includes topsideopen major vessel with branch pipe in the bottom side portion to supplyfluid and opening in the bottom to create free-falling even stream,collecting tank to remove liquid running over the top of the majorvessel and discharging as falling jet, transmitter located over liquidsurface and sending light flux through falling jet next to whichphotoelectric receiver is installed with the axis perpendicular to jetdirection. Transmitter and photoelectric receiver outputs are connectedto control and signal processing circuit.

The device is featured with the following disadvantages: complexity tomaintain uniform cross section of the jet in severe contaminationconditions when outlet opening gradually becomes contracted withdeposits, along with photoelectric receiver or transmitter dimming andspattering possibility causing inaccuracy of measurement.

Contactless in-flow turbidity meter is also available. Instrumentconsists of topside open major vessel with branch pipe in the bottomside portion to supply fluid, collecting tank to dispose liquid runningover the top of the major vessel, transmitter and photoelectric receiverlocated over liquid surface. Major vessel is arranged vertically, secondtransmitter and second photoelectric receiver are also placed overliquid surface, transmitters' and photoelectric receivers' axes areparallel and vertical, they are coplanar, transmitters' axes are facedto major vessel's walls and photoelectric receivers' axes—to the centerof the vessel. First transmitter and photoelectric receiver are dividedwith vertical opaque baffle with horizontal slot being in the liquid inproximity to its surface, and bottom edge folded to vessel's center andnot contacting major vessel bottom. Second transmitter and photoelectricreceiver are located symmetrically to the first ones with respect tovessel axis and are also divided with similar baffle, outputs of alltransmitters and photoelectric receivers are connected to control andsignals processing circuit (RU 2235310, G01N21/49, published 27 Aug.2004). It was accepted as a prototype.

Same source describes continuous water monitoring, emulsion andsuspensions concentration measurements with optical method. It wasaccepted as prototype of the claimed method.

In compliance with this method controlled liquid flows continuously tothe major vessel through piping. Liquid goes up along mid and both sidewalls of the vessel, then overflows vessel walls. In such a way vessel'stop portion has fixed level free liquid surface. Disposed liquid iscollected in collection tank and is drained to the pipeline with gravityflow. At the beginning of measurement cycle control and signalprocessing circuit activates transmitter's emission pulse. Such emissionwill not cause first photoelectric receiver's flashing even undertransmitter's divergent stream at zero particles content, as liquidsurface reflections are prevented by top portion of the baffle, andvessel bottom reflections are cut-off due to near-bottom bend of thesame baffle. Baffle slot is done in such a way to prevent transmitter'sbeam coming to this slot edges at zero particles content. Suspendedparticles concentration increase causes increase of the portion ofstream being horizontally dispersed by the particles and passing overthe slot, wherein dispersed stream passed beyond the slot left to rightwill decrease with exponential dependence in compliance withBouguer-lambert-Beer law. Horizontal stream dissipates in all thedirections, including liquid surface direction. Brightness of emissionfrom surface is measured by the first and second photoelectricreceivers. Moreover under photoelectric receivers' identityphoto-electric current I_(1L) at first photoelectric receiver's outputwill always be higher than photo-electric current I_(2L) at the secondphotoelectric receiver's output and be higher turbidity (particlescontent c) will be, the higher first to second ratio multiplicity willbecome. L index corresponds to the left active transmitter. MeasuredI_(1L) and I_(2L) values are stored to circuit's operative memory.Further on same circuit turns off transmitter, turns on the othertransmitter 6 (right-hand in the diagram) and same way as it was in thefirst cycle of operation measures photo-electric currents of the firstand second photoelectric receivers. In this case second photoelectricreceiver's photo-electric current will be higher than first one's.Similar way I_(1R) and I_(2R) values are stored to circuit's randomaccess memory. Then circuit calculates next relation being the functionof concentration and does not depend on data communication (optic)channel instability

$\begin{matrix}{{R = {\frac{I_{1L} \cdot I_{2R}}{I_{2L} \cdot I_{1R}} = {F(c)}}},} & (1)\end{matrix}$

whereas R is computational result,

I_(1L), I_(2L)—photo-electric currents of the first and secondphotoelectric receivers accordingly with left hand transmitter on;

I_(1R), I_(2R)—photo-electric currents of the first and secondphotoelectric receivers accordingly with right hand transmitter on;

F(c)—some function of Concentration of suspended particles

Then with calibration curve pre-stored to the memory the desiredconcentration c=φ(R) is found, whereas φ is function reverse to F.Computed value will be transmitted to (an external) equipment(indicators, control devices, etc.) through interface cable.

Thereupon cycle repeats.

Same source describes non-contact type in-flow turbidity meter,consisting of topside open major vessel with branch pipe in the bottomside portion to supply fluid, collecting tank to dispose liquid runningover the top of the major vessel, transmitter and photoelectric receiverlocated over liquid surface. Major vessel is arranged vertically, secondtransmitter and second photoelectric receiver are also placed overliquid surface, transmitters' and photoelectric receivers' axes areparallel and vertical, they are coplanar, transmitters' axes are facedto major vessel walls and photoelectric receivers' axes—to the center ofthe vessel. First transmitter and photoelectric receiver are dividedwith vertical light tight baffle with horizontal slot being in theliquid in proximity to its surface, and bottom edge folded to vessel'scenter and not contacting major vessel bottom. Second transmitter andphotoelectric receiver are located symmetrically to the first ones withrespect to vessel axis and are also divided with similar baffle, outputsof all transmitters and photoelectric receivers are connected to controland signals processing circuit.

Method disadvantage is that it allows to identify general contaminationbased on water surface layer reflection and does not allow to identifypollution class or type. Herewith the shortages of the device itselfaffect result reliability. Device shortage is in low metrologicalreliability of measuring equipment caused by the fact that possibledeterioration (possible changes in windows transparency of transmitterand photoelectric receiver) of transmitter and photoelectric receiverwindows clarity (due to fogging, splashing, dusting, and ageing) willcause inaccuracy of measurements. Transmitter and photoelectric receiverparameters instability will also result in measurement inaccuracy.Liquid consumption variation can cause minor (1-3 mm) change of liquidlevel which will also result in signal change at photoelectric receiveroutput. Evident error can also be caused by re-reflection from vesselbottom and walls and diffuse reflection from liquid surface.

There is provided a method and system that achieve reliability ofacquired data and simplification of the device to get high qualitypicture with respect to liquid or air pollution class.

Said technical result for this method is reached through particlesdetection in liquid based on the principle when light flux is passedthrough analyzed liquid from transmitter side and photoelectric receiverrecord light flux intensity at the output from analyzed liquid, whileliquid pollution is assessed with amount of difference in light fluxincoming analyzed liquid and light fluxes going out of it. Transmittersends light flux to analyzed liquid at varied pulse frequency, pulsesintensity and light wave length in various ranges of nanometers each ofwhich corresponds to specific type of polluting particles. Thecomparison is done between light fluxes incoming to analyzed liquid andout coming it for each range of light wave length and incase differenceidentified detect admixtures in the liquid corresponding the type ofpollutions causing change in liquid's absorption properties.

Reported technical result for devices is achieved by means of particlesin liquid detection system containing light flux source and oppositelyarranged receiver of light flux passed through analyzed liquid, lightflux intensity comparator unit to compare light fluxes intensity priorto passing through analyzed liquid and after it connected withcomputer-aided device to identify pollution type with absorptionproperties of liquid as well as facilities to supply and remove analyzedliquid from light flux passage area; it is equipped with all-glass tubewith analyzed liquid supply nozzle and the other one—with analyzedliquid removal nozzle. Transmitter is the unit installed at the end ofglass pipe with mounted nozzle to supply analyzed liquid. Transmitterincludes lens arranged immediately in front of glass tube inlet, withinclined optically transparent plate arranged ahead of it used to directto lens light fluxes from specific source of light emission located withemission direction vector oriented to this plate, along with light fluxintensity sensor located over optically transparent plate, Receiver torecord light flux consists of the unit installed at the end of glasspipe with mounted nozzle of analyzed liquid release, including lensopposite to which beam splitter is located along with IR and UVreceivers of light emission from beam splitter.

Herewith computer-aided device has control function to supply light fluxfrom individual emitting sources to analyzed liquid in pulses withvariety of pulse frequencies, intensity and light wave length in variousranges of nanometers, each of which corresponds to individual type ofpollution particles, and comparison function to compare light fluxentering analyzed liquid and light flux out coming such liquid for eachrange of light wave length and in case difference identified—to identifyforeign particles presence in the liquid corresponding to the type ofpollution causing liquid's absorption properties change.

Said technical result for this method is also reached through particlesdetection in the air based on the principle when analyzed air is passedthrough liquid then when air is passed through liquid light flux issupplied from transmitter side and passes through liquid andphotoelectric receiver records light flux intensity at liquid output,while transmitter sends light flux to the liquid at varied pulsefrequency, pulses intensity and light wave length in various ranges ofnanometers each of which corresponds specific type of pollutingparticles. The comparison is done between light fluxes incoming to theliquid and out coming it for each range of light wave length and in casedifference identified detect admixtures in the air corresponding thetype of pollutions causing change in liquid's absorption properties.

Said features are essential ones and interconnected with steady set ofessential features creation sufficient to get required technical result.

This invention is explained with embodiment which although is not theonly one possible, however clearly demonstrate possibility to reachrequired technical result with brought cumulative features.

In accordance with the present invention new approach to particlesdetection (identification) in liquid is considered.

Particles (or elements) here mean pollutions which can present inliquid—water, in the form of microparticles or nanoparticles. Pollutionhere means:

-   -   biological (bacteria, viruses, various microorganisms, etc.).    -   chemical (any types of toxins, traces of chemical agents,        detergents, fragments of mineral fertilizers and inorganic        fertilizers, medicinal preparations, etc.)    -   general contamination.

Particles in liquid detection method, first of all the particlescontaminating liquid, is based on the principle when light flux ispassed through analyzed liquid from transmitter side and photoelectricreceiver records light flux intensity at the output from analyzedliquid, while liquid pollution is assessed with amount of difference inlight flux incoming analyzed liquid and light fluxes going out of it.This principle is widely used at the moment. However this techniqueallows detecting single type or class of pollution only. It is caused bythe fact that liquid transparency depends on the wave length of lightemission going through analyzed liquid. The result is also affected withavailability of light reflecting components and causing interferenceelements, which are always present in the liquid or its environment.

To allow reliable result obtaining and to provide possibility toidentify not only specific type of pollution and not only total haze,but to detail class or type of pollution new method suggests to supplylight flux from transmitter to the liquid subject to analysis in pulseswith diverse pulses frequency, intensity and wave length in variousrange of nanometers each of which corresponds to specific type ofpollution particles.

Then comparison of light flux coming into analyzed liquid and going outof it is done for each range of light wave length and in case differenceis found, foreign particles presence in the liquid is identifiedcorresponding to the type of pollution causing liquid absorptionproperties change.

Method is based on the principle of light with certain wave lengtheffect on micro particles present in transparent liquid (in thisparticular case in the water). The following analysis procedure is doneusing above stated principle.

Light flux of various wave length and intensity selected depending onthe purpose of analysis passes through analyzed liquid. Thus wave lengthof 280-285 nanometers length is used to identify bio particles. Toidentify other type particles wave length shall be selected in such away to provide maximum effect on the particles. Light flux is suppliedin pulses of different frequency and intensity. Frequency modulation isused to advance noise stability. Intensive random motion of analyzedparticles in the liquid is reached with special algorithm to controlabove mentioned parameters of the light flux. It results in testedliquid's absorption properties change sensed by receiving sensor.Obtained data is processed with special algorithm. Processing resultsallow identifying micro particles concentration with high sensitivity,up to several dozens of micro particles in 1 milliliter of liquid.

In such a way offered method has sufficient versatility, allowing usingit to design and manufacture device to analyze both liquids and gases.

Light effect is used to excite intensive random movement of microparticles in the liquid. It causes liquid absorption properties change.

Light flux is supplied in pulses. Varying pulse frequency, intensity andlight wave length we get maximum value of light absorption by analyzedliquid.

Algorithm has been developed allowing identifying micro particles in theliquid with high sensitivity level based on light absorption.

This technique is realized by the following system, which can beinstalled as follows:

-   -   in water supply system: cities, building clusters, residential        houses, industrial facilities and any other sites requiring        continuous monitoring of water quality. It is connected to water        supply systems with branch pipe. The system operates        independently and in case water pollution sends signals to        control center defining pollution location and degree.    -   open water. Devices can be installed in the various sports of        open water having even water quality. Analyzed water is pumped        to the device with micro pump (included in device's scope of        supply). In case pollution sends signal to control center        indicating pollution location and degree. Number of devices        required per one basin is established depending on water quality        heterogeneity and number of areas with various degree of        uniformity.

In compliance with the invention particles in liquid detecting systemcontains liquid flux transmitter 1 and arranged opposite to it lightsensor 2 to record light flux passed through analyzed liquid, as well asanalyzed liquid supply means 3 and release means 4 to take it out ofluminous flux (FIGS. 1 and 2).

The system is equipped with glass tube 5, one end of which hasconnection branch 6 to supply analyzed liquid, and the other end hasconnection branch 7 mounted to release analyzed liquid.

Transmitter (FIG. 3) is unit 8 mounted at the end of glass tube 5 withanalyzed liquid branch connection 6 installed on it.

Said unit 8 includes lens 9, placed immediately pre-entry to the glasstube 5, in front of which inclined optically transparent plate 10arranged to direct to lens side 9 lights\fluxes from 11 (LED-sources

) individual sources of luminous radiation arranged with radiationvector oriented to this plate. Unit also contains light intensity sensor12 located over optically transparent plate.

Receiver (FIG. 4) to record light flux is unit 13 mounted at the end ofglass tube 5 having branch connection 7 to release analyzed liquid. Thisunit 13 includes lens 14 at glass lens outlet. Beam splitter 15 isarranged opposite to lens 14, and beam splitter's light flux receiversIR 16

UV 17 are located behind the beam splitter.

System operates based on light fluxes comparison principle comparinglight flux prior to its passage through analyzed liquid and post-passageone. This data is communicated through corresponding unit tocomputer-aided device 18 (also referred to as controller) to identifypollution type through change of liquid's absorption properties incompliance with preprogrammed algorithm in compliance with which eachtype pollution is manifested with liquid light absorption propertiesdecrease at the certain light wave. The system may also include acommunication unit 19 for communicating with other devices such as aserver, another computer, another particles in liquid detecting system.The communication may be a short range transmission, long rangetransmission, wireless communication, wired communication and type ofknown communication.

This computer-aided device 18 has control function to control individuallight emission sources supplying light flux to analyzed liquid in pulseswith various pulse frequency, intensity and light wave length in variousranges of nanometers, each of which corresponds to individual type ofpollution particles, and comparison function to compare light fluxentering analyzed liquid and light flux out coming such liquid for eachrange of light wave length and in case difference identified—to identifyforeign particles presence in the liquid corresponding to the type ofpollution causing liquid's absorption properties change.

This system:

a. Allows detecting various types of the particles and theirconcentration, including bio particles, provided high sensitivity level.b. Has quite simple design and is cheap to fabricate. Its fair overalldimensions make it possible to place the device in diverse locations.c. The device has quite high reliability degree due to simple design.d. The device does not require auxiliary facilities or materials tocalibrate it.e. The device is easy to operate and cost effective, it does not requireany consumables.f. Analysis results can be electronically communicated to controlcenter.

Same principle is used to analyze air pollution. To do that air (gas)flows through special chamber (bubble flask) where air (gas) is absorbedby liquid. Then liquid is subjected to analysis based on above method.It allows detecting various contaminating particles presence in the air(gas) with high sensitivity.

Claimed method to detect pollutions in the liquid can be also used todetect particles in the air. This alternate method consists in thatanalyzed air is sent through liquid (with pre-set known and invariableoptical properties), then while air passes through the liquid light fluxis sent through the liquid from transmitter side and light flux receiverrecord light flux intensity as it lease the liquid.

Therewith transmitter's light flux is sent to the liquid in pulses withvariable pulse frequency, and light wave length in various ranges ofnanometers each of which corresponds to specific type of pollutionparticles. Then light flux entering liquid and light flux leaving it arecompared for each range of light wave length and in case difference isfound, foreign particles in the air are identified corresponding to thetype of pollution causing liquid absorption properties change.

This alternate method is working based on the same principle withdescribed above pollution detection in liquid. When polluted air comesinto the liquid with known optical properties, liquid optical propertieschange.

See in FIG. 5 flow chart of the device allowing evaluating airpollution. Pumped with pump 20 (compressed air pump) the air passesthrough tube 21 to the bath 22 filled with liquid, where it is blendedwith the liquid. Thereupon air leaves liquid (as tube has positivepressure) and rising up in the cavity around the tube is released toatmosphere through outlet connection 23. This device uses bubble flaskto detect particles in the air. Bubble flask includes tubular body withplugged ends one of which functions as bottom of analyzed liquid bath,tube to supply air in bath bottom direction arranged in this body, withopenings letting air to pass from the tube to bath cavity done in thebottom portion of the tube. Tube's external wall and body internal wallis featured with boss arrangements or indentations to create labyrinthform air passage from bath to atmosphere.

Bath bottom is featured with indentations or boss arrangements to mixliquid and air passing through it and body walls in bath area openingsare done to connect analyzed liquid supply and removal devices.

The device is also equipped with particles detecting in water system 24designed same ways as above described system pictured on the FIG. 2-4.Reliable data obtaining algorithm is based on water pollution transferto air pollution and vice versa.

FIG. 6 shows general view and arrangement of the device to detectparticles in the air using liquid (water). Bubble flask 26 is fixed inthe body 25 (FIG. 7). Bubble flask consists of the tube 27 with airsupplied to the top of it from suction fan 28. Tube 27 is immersed tothe bath 29 and has in its lower portion immersed to the bath nearby thebottom openings 30 to provide fractional output of pressurized air tobath cavity 31. Bath cavity is filled with liquid (water). Specificfeature of bath design is the necessity to provide air and water mixingwhile air passaging through liquid to create homogenous gas-liquidmedium. This is achieved with indentations and/or bosses 32 arranged onbath bottom and probably on its walls, or other elements facilitatingliquid and air bubbling (mixing them) and with labyrinth formdisplacement of air leaving the liquid. Also boss arrangements 33 areprovided on internal wall of bubbling flask's tubular body internal walland external surface of tube 27 to decelerate air leaving the bath withlabyrinth form air stream movement released to atmosphere through theopening in bubble flask tubular body 34 wall, which can be used toinstall connecting branch 23. These design features of bubble flask areintentionally done to achieve liquid in bath homogenous mixing with airthroughout the bath. It is necessary as optical component's liquidanalysis is done on condition that liquid is homogenous with regards tostructural composition and volume. Herewith these bosses orindentations, or other elements are used to take liquid splashesentrapped by air back to the bath.

Body 25 also contains load cell 35 of the bubble flask 26, connectedwith control valve 36, liquid level sensor 37, installed in accumulatortank 38, connected with bubble flask, dispenser micro pumps unit 39 usedto maintain pre-set liquid level in the bath and in glass tube 5 withunit 8 and 13 at its ends arranged in full concordance with earlierdescribed design in compliance with FIG. 2-4, and electronic controlunit.

Connecting branches of units 8 and 13 are connected to bubble flask bathin such a way to provide liquid passage through the tube.

This invention is industrially applicable and can be used forenvironmental monitoring.

There may be provide a method for detecting particles in a liquid, themethod may include having a light flux to pass through analyzed liquidfrom transmitter side and as it outcomes analyzed liquid light fluxreceiver records light flux intensity, herewith liquid pollution isevaluated with the difference of light flux entering liquid and lightflux leaving it, light flux is sent to analyzed liquid from transmitterin pulses of various frequency, intensity and light wave length in thevarious ranges of nanometers each of which corresponds to individualtype pollution particles, then comparison of light flux enteringanalyzed liquid and leaving it is done for each range of light wavelength and in case difference is found, foreign particles in liquid areidentified corresponding the type of pollution causing liquid absorptionproperties change.

There may be provided a system. Particles in liquid detection systemincluding light flux transmitter and located opposite to it receiver torecord light flux passed through analyzed liquid, comparator unit tocompare light flux intensity prior to its entry to analyzed liquid andafter its leaving it connected with computer-aided device to detectpollution type based on liquid absorption properties change, as well asdevice to supply and remove analyzed liquid from light flux passagearea, it is completed with glass tube one end of which has connectingbranch to supply analyzed liquid and the other one has connection branchto remove analyzed liquid. Transmitter is the unit installed at the endof glass pipe with mounted nozzle of analyzed liquid supply. Transmitterincludes lens arranged immediately in front of glass tube inlet, withinclined optically transparent plate arranged in front of it used todirect to lens light fluxes from individual source of light emissionlocated with emission direction vector oriented to this plate, alongwith light flux intensity sensor located over optically transparentplate. Receiver to record light flux consists of the unit installed overoptically transparent plate. Light emission flux receiver is the unitinstalled at the end of glass tube with connecting branch mounted toremove analyzed liquid. This unit contains lens arranged at glass tubeoutlet opposite to which inclined beam splitter and IR and UV sensors toreceive light emitted by beam splitter are arranged.

The system has a computer-aided device that has control function ofindividual light sources supplying light flux to analyzed liquid inpulses of varying frequency, intensity and light wave length in thevarious ranges of nanometers, each of which corresponds to individualtype pollution particles, then comparison of light flux enteringanalyzed liquid and leaving it is done for each range of light wavelength and in case difference is found, foreign particles in liquid areidentified corresponding the type of pollution causing liquid absorptionproperties change.

The method may include sending analyzed air through liquid, then whileair passes through the liquid light flux is sent through the liquid fromtransmitter side and light flux receiver record light flux intensity asit leaves the liquid. Therewith transmitter's light flux is sent to theliquid in pulses with variable pulse frequency, and light wave length invarious ranges of nanometers each of which corresponds specific type ofpollution particles. Then light flux entering liquid and light fluxleaving it are compared for each range of light wave length and in casedifference is found, foreign particles in the air are identifiedcorresponding to the type of pollution causing liquid absorptionproperties change.

The system may include a bubble flask to mix air and water, light fluxtransmitter and arranged oppositely receiver to record light flux passedthrough analyzed liquid, comparator unit to compare light flux prior toit coming into analyzed liquid and after it leaving analyzed liquid,connected with computer-aided device to detect type of pollution basedon liquid absorption properties change, along with devices to supply andremove analyzed liquid from light flux passage area, the system isequipped with glass tube, one end of which has connection branch tosupply analyzed liquid coming from bubble flask, and the other end hasconnection branch mounted to release analyzed liquid. Transmitter is theunit mounted at the end of glass tube with analyzed liquid supply branchconnection installed on it, including lens placed immediately pre-entryto the glass tube in front of which inclined optically transparent plateis located to direct light fluxes from individual light sources withlight vector directed to this plate, to lens side, and light fluxintensity sensor arranged over optically transparent plate. Receiver torecord light flux is the unit installed on the end of glass tube withanalyzed liquid release connection branch mounted on it, including lensat glass tube outlet with inclined beam splitter opposite to it and beamsplitter's IR and UV light flux receivers.

Bubble flask used to detect particles in the air includes tubular bodywith plugged ends one of which functions as bottom of analyzed liquidbath, tube to supply air in bath bottom direction arranged in this body,with openings letting air to pass from the tube to bath cavity done inthe bottom portion of the tube. Tube's external wall and body internalwall is featured with boss arrangements or indentations to createlabyrinth form air passage from bath to atmosphere.

The bubble flask has indentations or boss arrangements done on bath'sbottom to mix liquid and air passing through it.

The bubble flask may have openings done in body walls in bath area toconnect analyzed liquid supply and removal devices.

FIG. 8 illustrates a system according to an embodiment of the invention.FIG. 8 illustrates a system in which an inlet 301 of the bath 22 andoutlet 302 of the bath are liquidly coupled to each other—fluid thatexits outlet 302 may pass through one or more liquid conduits beforereentering inlet 301. Fluid may be supplied to inlet 301 via firstsampling point 201. Some or all of the liquid may be drained (or sentoutside the loop between inlet 301 and outlet 302) via outlet 303. Thefirst sampling point 201 may supply liquid in a continuous ornon-continuous manner during the analysis process. Outlet 202 may drainliquid in a continuous or non-continuous manner after or during theanalysis process.

FIG. 9 illustrates a system 101 and a monitored device 201 (such as acontainer, a liquid purifier or any other device that may process theliquid) according to an embodiment of the invention. First samplingpoint 201 precedes the monitored device 201. Second sampling point 202follows the monitored device 201.

Switch 111 is liquidly coupled to first and second sampling points 201and 202 and may select which sampling point to open. This allows toanalyze the liquid before and after the monitored device operated on thefluid—and evaluate the quality, efficiency (or any other parameter) ofthe process executed by the monitored device.

Liquid outputted from system 101 may be drained or sent elsewhere.

It should be noted that different monitored devices may requiredifferent liquid purity levels. A liquid purifier may be required toprovide a purer liquid that a storage container.

Deviations from a require liquid purity may trigger an alert.

FIG. 10 illustrates two systems 101 and 102 monitored device 201according to an embodiment of the invention.

In FIG. 10 there is no switch—system 101 analyzes liquid from firstsampling point 201 and system 102 analyzes liquid from second samplingpoint 202.

Liquid outputted from each one of system 101 and system 102 may bedrained or sent elsewhere.

FIG. 11 illustrates a system and a monitored device according to anembodiment of the invention.

System 101 is liquidly coupled to multiple sampling points 201, 202 and203 and may sample (via a switch—not shown) the fluid from thesesampling points. First sampling point 201 precedes the monitored device202 (such as building water reservoir), second and third sampling points202 and 203 may receive fluid from different locations of the monitoreddevice 202.

FIG. 12 multiple sampling points and an irrigation system according toan embodiment of the invention.

The irrigation system includes water source 211, pumps 212, watertreatment plant 213, water reservoir 214 of a distribution system,multiple branches 215, 216, 217 and 218 (leading to differentbuildings).

First sampling point 201 is positioned between pumps 212 and watertreatment plant 213.

Second sampling point 202 is positioned between water treatment plant213 and water reservoir 214.

Third sampling point 203 is located after water reservoir 214 and beforebranches 215-218.

Fourth sampling point 204 is located after third sampling point—butprecedes branches 215-218.

Fifth sampling point 205 is located within branch 215.

Sixth sampling point 206 is located within branch 216.

Seventh sampling point 207 is located within branch 217.

Sixth sampling point 208 is located within branch 218.

FIG. 13 illustrates a system and a cleaning unit according to anembodiment of the invention.

System 101 has a fluid inlet that is fed (with fluid) by switch 111.System 101 may send control signals for controlling switch 111. System101 includes antenna 191 (of communication unit) and may also include anoutlet that may output liquid to the drain (or to another location).

Switch 111 includes a first inlet 1111 and a second inlet 1112. Thefirst inlet 1111 receives liquid from first sampling point 201 (thatsamples liquid from conduit 250). The second inlet 1112 receives liquid(with cleaning materials) from cleaning unit 220. Cleaning unit may befed by fluid from first sampling point 201 and may mix the liquid with acleaning solvent.

When the system 101 is cleaned—switch 111 selects second inlet 1112.Else—switch 111 may select inlet 1111.

FIG. 14 illustrates a switch according to an embodiment of theinvention.

First inlet 1111 is followed by first valve 43.

Second inlet 1112 is followed by second valve 44.

First and second valves are followed by mixer 41 and outlet 3.

First and second valves 43 and 44 may be opened or closed in order todetermine which fluid will be outputted by switch 111.

Cleaning unit 220 is illustrated as including a container 47 forreceiving cleaning material (such as a cleaning solvent) that is mixed(48) with fluid (denoted 46).

FIG. 15 illustrates a system and multiple monitored device according toan embodiment of the invention.

System 101 is coupled to switch 111 that may receive fluid from a firstsampling point 201 and from a second sampling point 202. The firstsampling point 201 precedes manufacturing units 205, 206 and 207 whilethe second sampling point follows manufacturing units 205, 206 and 207.

The manufacturing units 205, 206 and 207 may process liquid, may be asource of liquid (such as but not limited to milk).

The liquid from manufacturing units 205, 206 and 207 may be controlledby valves 255, 256 and 257 respectively. Cleaning solutions stored incleaning solution reservoirs 221-224 may be fed (for example via firstsampling point 201) to manufacturing units 205, 206 and 207.

During a cleaning process.

System 101 may transmit information (such as analysis results) to acontrol system 410. Any type of control system 410 may be provided. Thecontrol system may be manned or unmanned. A person may receive analysisinformation from system 101. The control system 410 may control system101, and/or switch 111 and/or first and second sampling points, and/orcleaning solution reservoirs and/or manufacturing units 205, 206 and207.

FIG. 16 illustrates a system and a sampling unit 270 according to anembodiment of the invention.

Sampling unit 270 may be included within system 101.

Sampling unit 270 may include one or more containers 271 for receivingfluid (under the control of system 101) once system 101 determined thata certain event occurred (for example—the liquid was polluted by acertain foreign particle, the overall level of pollution has exceeds athreshold and/or was below the threshold or equaled the threshold, theoverall level of a certain foreign particle exceeded a threshold and/orwas below the threshold or equaled the threshold). The sampling by thesampling unit 270 may be triggered periodically, in any predefinedmanner, in a random manner, in a pseudo random manner and the like.

Once a sampling is triggered the sampling unit 270 obtains a sample ofthe liquid that was just analyzed by system 101 and stores the sample ata container 271.

The container 271 may be maintained in predefined conditions (forexample at a certain temperature)—by unit 272 (for example acooler)—until the sample (and possible the container 271) are taken forfurther analysis.

Sampling unit 270 allows real time sampling of the liquid.

It has been found that the transmission of pulses that comprisefrequency components within a first frequency range that correspond to afirst wavelength range of 750 to 820 nanometers provide informationabout the overall turbidity of the liquid, pulses that comprisefrequency components within a second frequency range that correspond toa second wavelength range of 280 to 285 nanometers provide informationabout the presence of bacteria and pulses that comprise frequencycomponents within a third frequency range that corresponds to a thirdwavelength range of 450 to 454 nanometers provide information aboutorganic materials.

According to an embodiment of the invention the presence of bacteria (ora significant presence of bacteria) may be sensed when the ratio between(a) the intensity of detection signals detected as a result of thetransmission of second frequency range pulses and (b) the intensity ofdetection signals detected as a result of the transmission of firstfrequency range pulses—exceeds two or three.

According to an embodiment of the invention the presence of organicmaterials (or a significant presence of organic material) may be sensedwhen the ratio between (a) the intensity of detection signals detectedas a result of the transmission of third frequency range pulses and (b)the intensity of detection signals detected as a result of thetransmission of first frequency range pulses—exceeds two or three.

During a multiple phase cleaning process different chemicals may beapplied and these phases (at least a completion criterion for thecompletion of the phases) may be measured by different iterations offluid analysis. The last phase may include cleaning by pure water- andthe analysis may include transmitting first frequency range pulses andat least one out of second frequency range pulses and third frequencyrange pulses. Previous phases may be monitored by using (for example)only first frequency range pulses. Any combination of pulses may be usedfor monitoring each phase.

FIG. 17 illustrates method 300 according to an embodiment of theinvention.

Method 300 may start by steps 320 and 330.

Step 320 may include supplying, by a fluid inlet, liquid to a liquidconduit and outputting the fluid from the fluid conduit by a fluidoutlet. A portion of each one of the fluid inlet and the fluid outletmay or may not be oriented to the fluid conduit. See, for example, FIGS.3 and 4.

The fluid inlet may or may not be fluidly coupled to the fluid outlet.See, for example FIG. 8 versus FIGS. 9-12.

The fluid conduit may have an inner layer that may be at least partiallytransparent and an external layer that may be reflective. In this fluidconduit the pulses may be reflected from the inner layer (refractiondifference between the fluid and the inner layer) and also from theexternal layer.

Using such a fluid conduit increases the sensitivity of the liquidcontamination measurements because the number of received pulsesincreases due to reflections and/or scattering from the inner and outerlayers.

The fluid conduit may have an inner layer that may be reflective. Inthis fluid conduit the pulses will be reflected from the inner layer.

Step 330 may include transmitting multiple transmitted pulses ofradiation, by a transmitter, towards a liquid conduit that may be filledwith liquid.

The multiple transmitted pulses may include pulses that differ from eachby being associated with absorbance frequencies of different foreignparticles.

The transmitted pulses may be of the same intensity or may differ fromeach other by intensity. Some pulses may be of the same intensity whileother pulses may differ from each other by their intensity.

For example, the transmitted pulses may include a first set of pulsesthat are associated with first absorbance frequencies associated with afirst foreign particle and may include a second set of pulses that areassociated with second absorbance frequencies associated with a secondforeign particle that differs from the first foreign particle.

The number of sets (and the number of different absorbance frequencies)may exceed two, may exceed three, and the like.

The transmitted pulses may include pulses that provide an indicationabout the overall turbidity of the fluid.

The transmitted pulses may include ultra violet pulses and infraredpulses. Step 330 may include generating the ultra violet pulses by anultra violet source and generating the infrared pulses by an infraredsource

The ultra violet source may have an optical axis that may be normal, ororiented or parallel to an optical axis of the infrared source.

Step 330 may also include detecting intensities of the transmittedpulses before the passage of the transmitted pulses through the liquid.

Step 330 may include, for example, transmitting transmitted pulses thatmay include any combination of the following: (a) one or more pulsesthat may include frequency components within a first frequency rangethat correspond to a first wavelength range of 750 to 820 nanometers,(b) one or more pulses that may include frequency components within asecond frequency range that correspond to a second wavelength range of280 to 285 nanometers, and (c) one or more pulses that may includefrequency components within a third frequency range that corresponds toa third wavelength range of 450 to 454 nanometers.

Step 330 may be followed by step 340 of receiving, by a receiver,received pulses that propagated through liquid as a result of thetransmission of the transmitted pulses. It is noted that the number ofreceived pulses may differ from the number of the transmitted pulses.For example—the number of received pulses may increase as a result ofscattering and/or reflection from the liquid conduit and/or from theforeign particles in the liquid. Yet for another example—the number ofreceived pulses may decrease due to a total absorbance of one or moretransmitted pulses.

Step 340 may also include detecting intensities of the received pulses.

Step 330 may be executed by a transmitter that may include a transmitterlens that is arranged immediately in front of the first side of thetransparent pipe. Step 340 may be executed by a receiver that mayinclude a receiver lens that is arranged immediately after the secondside of the transparent pipe. The transmitter lens may be preceded by atransmitter beam splitter and the receiver lens may be preceded by areceiver beam splitter.

Steps 330 and 340 may be followed by step 350 of comparing between thetransmitted pulses and the received pulses to provide a comparisonresult. The comparison may include comparing between intensities of thetransmitted pulses and the received pulses. The comparison resultprovides an indication about the absorbance of the pulses within theliquid. The comparison result may provide an indication about theattenuation per absorbance frequency range.

There are multiple transmitted pulses and multiple received pulses andthe comparison result may be generated by applying any function(statistical or not) on the intensities of these multiple pulses.

Step 350 may be followed by step 360 of determining a liquidcontamination based on the comparison result.

The relationship between the attenuation and the liquid contaminationmay be learnt during a learning period, may be provided as a look uptable or an equation (or in any other manner). The mapping may differfrom one foreign particle to another—but this is not necessarily so.

One or more iterations of steps 320, 330, 340, 350 and 360 may beexecuted.

After one or more iterations of steps 320, 330, 340, 350 and 360 themethod may include step 370 of cleaning the liquid conduit with acleaning solution.

Step 370 may be triggered based on the liquid contamination (forexample—when step 360 decides that the liquid is within a contaminationrange that will require the liquid conduit (exposed to the liquid) to becleaned. The triggering may be responsive to both contamination levelsand time periods during which the contamination levels existed.

Step 370 may include selecting, out of a first fluid inlet for providingthe liquid and a second fluid inlet for providing the cleaning solution,the second fluid inlet. See, for example, FIGS. 13 and 14.

When multiple iterations of steps 320, 330, 340, 350 and 360 areexecuted the method may include generating statistics that reflect theoutcome of the multiple iterations.

According to an embodiment of the invention step 320 may be preceded bystep 310 of selecting which liquid to analyze.

Step 310 may be executed by the foreign particle detection system or byanother entity (such as but not limited to control system 410).

Step 310 may include, for example, selecting a selected sampling pointout of multiple sampling points that are liquidly coupled to the liquidconduit.

The selection of the sampling point may involve selecting a liquid pathout of multiple liquid paths.

Step 310 may include selecting configuration of a switch (see, forexample, FIG. 9), selecting a system for liquid analysis (see, forexample, FIG. 10) or selecting any other value of liquid control element(see, for example, valves 255, 256 and 257 of FIG. 15).

The selection may be repeated one or more—and different iterations ofsteps 320, 330, 340, 350 and 360 may be allocated for analyzing liquidsfrom different sources.

According to an embodiment of the invention the selection a firstiteration of the multiple iteration is preceded by selecting a firstliquid sampling point for providing a liquid to be analyzed during thefirst iteration. A second iteration of the multiple iterations ispreceded by selecting a second liquid sampling point for providing aliquid to be analyzed during the second iteration.

The execution of two (or more iterations) of steps 320, 330, 340, 350and 360 may include sampling the liquid from the first sampling pointbefore the liquid undergoes a certain process: and sampling the liquidfrom the second sampling point after the liquid undergoes the certainprocess.

When such sampling occurs method 300 may include step 380 of evaluatingthe certain process by comparing between outcomes of the first andsecond iterations. It is noted that the first sampling point may besampled during more than a single iteration and that the second samplingpoint may be sampled during more than a single iteration.

The certain process may be a liquid purification process, a storage ofthe liquid, a liquid manufacturing process, a liquid mixing process, andthe like.

Step 380 may include evaluating an efficiency of the liquid purificationprocess.

According to an embodiment of the invention multiple iterations of steps320, 330, 340, 350 and 360 are at different points of time—in order tomonitor the progress of a certain process.

Different iterations may be executed before, during and/or afterdifferent phases of the certain process.

At least two of the different iterations differ from each other by thepulses transmitted during the iterations.

The one of the different iterations may include transmitting (i) a firstset of pulses that comprises pulses that provide information about anoverall turbidity of the liquid and (ii) a second set of pulses thatcomprises pulses that correspond to second absorbance frequency of acertain type of foreign particles.

Another iteration one of the different iterations may includetransmitting only a first set of pulses that comprises pulses thatprovide information about an overall turbidity of the liquid.

The certain process may be a cleaning process of a certain system, thecleaning process may include multiple phases that may differ from eachother by the cleaning material that is being used. The properties of thedifferent cleaning materials (after passing through the certain system)may be monitoring using different transmitted pulses.

The completion of one or more phases may be dependent upon thecleanliness level of the certain system.

For example—the cleaning process may include multiple phases thatinvolve using clean water. The clean water may be used, for example,during the final phase of the cleaning process. The cleanliness of thewater may be evaluated by executing the iteration of steps 320-360.

According to an embodiment of the invention step 320 is preceded by step305 of mixing gas (to be evaluated) with an initial liquid to providethe liquid; and wherein the determining of the liquid contaminationcomprises determining the contamination of the gas. The term initialliquid is a liquid that is mixed with the gas to provide liquid (that ismonitored). The initial liquid may be of a known composition.

The gas may be air.

Step 305 may include at least one of the following:

-   -   a. Mixing the gas with the initial liquid comprises using a        bubble flask.    -   b. Pumping the air into an input conduit of the bubble flask,        the bottom of the bubble flask is immersed within the liquid.    -   c. Forcing air that exits the liquid to pass through a labyrinth        before exiting the bubble flask. The labyrinth may prevent the        air from propagating in a pure vertical path from the liquid to        an air outlet of the bubble flask.    -   d. Mixing the initial liquid and the air using a non-flat bath.        The non-flat bath may include at least one of indentations and        boss arrangements.

In the foregoing specification, the invention has been described withreference to specific examples of embodiments of the invention. It will,however, be evident that various modifications and changes may be madetherein without departing from the broader spirit and scope of theinvention as set forth in the appended claims.

Moreover, the terms “front,” “back,” “top,” “bottom,” “over,” “under”and the like in the description and in the claims, if any, are used fordescriptive purposes and not necessarily for describing permanentrelative positions. It is understood that the terms so used areinterchangeable under appropriate circumstances such that theembodiments of the invention described herein are, for example, capableof operation in other orientations than those illustrated or otherwisedescribed herein.

The connections as discussed herein may be any type of connectionsuitable to transfer signals from or to the respective nodes, units ordevices, for example via intermediate devices. Accordingly, unlessimplied or stated otherwise, the connections may for example be directconnections or indirect connections. The connections may be illustratedor described in reference to being a single connection, a plurality ofconnections, unidirectional connections, or bidirectional connections.However, different embodiments may vary the implementation of theconnections. For example, separate unidirectional connections may beused rather than bidirectional connections and vice versa. Also,plurality of connections may be replaced with a single connection thattransfers multiple signals serially or in a time multiplexed manner.Likewise, single connections carrying multiple signals may be separatedout into various different connections carrying subsets of thesesignals. Therefore, many options exist for transferring signals.

Although specific conductivity types or polarity of potentials have beendescribed in the examples, it will be appreciated that conductivitytypes and polarities of potentials may be reversed.

Each signal described herein may be designed as positive or negativelogic. In the case of a negative logic signal, the signal is active lowwhere the logically true state corresponds to a logic level zero. In thecase of a positive logic signal, the signal is active high where thelogically true state corresponds to a logic level one. Note that any ofthe signals described herein may be designed as either negative orpositive logic signals. Therefore, in alternate embodiments, thosesignals described as positive logic signals may be implemented asnegative logic signals, and those signals described as negative logicsignals may be implemented as positive logic signals.

Furthermore, the terms “assert” or “set” and “negate” (or “deassert” or“clear”) are used herein when referring to the rendering of a signal,status bit, or similar apparatus into its logically true or logicallyfalse state, respectively. If the logically true state is a logic levelone, the logically false state is a logic level zero. And if thelogically true state is a logic level zero, the logically false state isa logic level one.

Those skilled in the art will recognize that the boundaries betweenlogic blocks are merely illustrative and that alternative embodimentsmay merge logic blocks or circuit elements or impose an alternatedecomposition of functionality upon various logic blocks or circuitelements. Thus, it is to be understood that the architectures depictedherein are merely exemplary, and that in fact many other architecturesmay be implemented which achieve the same functionality.

Any arrangement of components to achieve the same functionality iseffectively “associated” such that the desired functionality isachieved. Hence, any two components herein combined to achieve aparticular functionality may be seen as “associated with” each othersuch that the desired functionality is achieved, irrespective ofarchitectures or intermedial components. Likewise, any two components soassociated can also be viewed as being “operably connected,” or“operably coupled,” to each other to achieve the desired functionality.

Furthermore, those skilled in the art will recognize that boundariesbetween the above described operations merely illustrative. The multipleoperations may be combined into a single operation, a single operationmay be distributed in additional operations and operations may beexecuted at least partially overlapping in time. Moreover, alternativeembodiments may include multiple instances of a particular operation,and the order of operations may be altered in various other embodiments.

However, other modifications, variations and alternatives are alsopossible. The specifications and drawings are, accordingly, to beregarded in an illustrative rather than in a restrictive sense.

In the claims, any reference signs placed between parentheses shall notbe construed as limiting the claim. The word ‘comprising’ does notexclude the presence of other elements or steps then those listed in aclaim. Furthermore, the terms “a” or “an,” as used herein, are definedas one or more than one. Also, the use of introductory phrases such as“at least one” and “one or more” in the claims should not be construedto imply that the introduction of another claim element by theindefinite articles “a” or “an” limits any particular claim containingsuch introduced claim element to inventions containing only one suchelement, even when the same claim includes the introductory phrases “oneor more” or “at least one” and indefinite articles such as “a” or “an.”The same holds true for the use of definite articles. Unless statedotherwise, terms such as “first” and “second” are used to arbitrarilydistinguish between the elements such terms describe. Thus, these termsare not necessarily intended to indicate temporal or otherprioritization of such elements. The mere fact that certain measures arerecited in mutually different claims does not indicate that acombination of these measures cannot be used to advantage.

While certain features of the invention have been illustrated anddescribed herein, many modifications, substitutions, changes, andequivalents will now occur to those of ordinary skill in the an. It is,therefore, to be understood that the appended claims are intended tocover all such modifications and changes as fall within the true spiritof the invention.

We claim:
 1. A method for detecting foreign particles in a liquid, themethod comprises: transmitting transmitted pulses of radiation, by atransmitter, towards a liquid conduit that is filled with liquid;wherein the transmitted pulses comprises pulses that differ from each bybeing associated with absorbance frequencies of different foreignparticles; receiving, by a receiver, received pulses that propagatedthrough liquid as a result of the transmission of multiple transmittedpulses; comparing between the transmitted pulses and the received pulsesto provide a comparison result; and determining a liquid contaminationbased on the comparison result.